Long-Term Effect of Total Cycle Time and Aerobic/Anoxic Phase Ratio on Nitrogen Removal in a Sequencing Batch Reactor
Abstract:A laboratory-scale sequencing batch reactor was used to study nitrogen removal from a synthetic wastewater with an ammonium-nitrogen concentration of 50 mg/L. The effect of two key parameters (i.e., the total cycle time and the aerobic/anoxic phase duration ratio) on the performance of the reactor was investigated. Four sets of operational parameters resulting from the combination of 6 and 8 hours of cycle time and 1:1 and 1:3 aerobic/anoxic ratios were studied. Denitrification was based mainly on endogenous carbon sources as long as organic carbon, provided in the form of acetate, was quickly removed from the mixed liquor during the aerobic phase of the reactor operation. In terms of nitrogen removal efficiency, the set of 8 hours of cycle time and 1:3 aerobic/anoxic phase ratio was found to be superior in that it consistently yielded an effluent total nitrogen concentration of less than 15 mg/L (consisting almost exclusively of nitrate-nitrogen) and exhibited a percentage nitrogen removal rate of 77 ± 2.5%. In terms of wastewater throughput (i.e., wastewater volume treated per day), however, the implementation of 6 hours of cycle time and 1:3 aerobic/anoxic phase ratio was satisfactory for nitrogen removal efficiency (72 ± 2%), although elevated amounts of ammonium- and nitrite-nitrogen were found in the effluent. It was also demonstrated that under certain operating conditions nitrogen removal via nitrite is observed, as nitratification (i.e., oxidation of nitrite-nitrogen to nitrate) and denitratification (i.e., reduction of nitrate-nitrogen to nitrite) are bypassed.
Document Type: Research Article
Publication date: 2002-07-01
More about this publication?
- Water Environment Research® (WER®) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year. Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- WEF Bookstore
- Ingenta Connect is not responsible for the content or availability of external websites